13 May 2025
Samantha Taylor
Job Title
Image: olezzo / Adobe Stock
Hypertension in cats has been described for many years, but challenges remain in the diagnosis and treatment of this condition in practice.
Hypertension occurs most commonly secondary to underlying diseases such as CKD and hyperthyroidism, and can result in various clinical signs affecting target organs (such as the brain, heart, kidneys and eyes).
This article aims to discuss what is new in feline hypertension and how we can work as a team to measure systolic blood pressure (SBP) more often, which will undoubtedly lead to more frequent diagnosis and treatment of the condition.
Hypertension is an area of growing research, with some recent publications providing useful information on the condition:
We are fortunate to have two options for treatment of hypertension licensed in the UK and other countries: amlodipine and telmisartan.
Amlodipine is generally the treatment of choice when SBP is equal to or more than 180mmHg, or target organ damage is present (www.iris-kidney.com), but telmisartan as an angiotensin receptor blocker may have some theoretical advantages, such as reduction of intraglomerular pressure and reducing proteinuria.
Further investigation is needed to untangle the relationship between prognosis, proteinuria and hypertension in cats. A “one size fits all” does not exist, as dosages may need adjustment, and comorbidities need managing. Monitoring is vital and need not be expensive, as we should take into account body condition and appetite, as well as reassessment of urea and creatinine, and the urine protein-creatinine ratio, for example.
As with all medications prescribed for cats, medication formulation preferences (tablets versus liquid) may also influence choice, and owners should be supported in administering chronic medication – emphasising that it is likely their cat will need antihypertensive medication for life. It is also important to follow up on diagnosed cases. As well as re-checking the SBP after seven to 10 days and adjusting the medication dosage, remember that most of these cats will have underlying disease – most commonly CKD – and so monitoring and management of both conditions is needed.
These are often fragile cats, and attending to aspects such as nutrition and stress, analgesia for osteoarthritis as a comorbidity is important for quality of life, and longevity.
Conroy et al (2018) examined survival after diagnosis of hypertension in 282 cats in the UK. Cats diagnosed as part of screening (due to pre-existing disease) had improved survival over those diagnosed due to clinical signs of hypertension (supporting the promotion of early diagnosis). Estimated median survival time of cats with seven or more days of follow up was 400 days (interquartile range 147-797). In this study, when the original larger group of cat consultations were analysed, a total of only 1 in 23 cats aged nine years or older had blood pressure assessed, showing room for improvement in identifying cases. The findings of this study support the experience that cats treated for hypertension can do well, with prolonged survival and good quality of life.
We cannot treat hypertension if we do not detect it, and barriers exist to bringing cats to the clinic – perhaps even more so with older cats. Signs can be subtle, and cats often will not be presented specifically for SBP assessment, rather for clinical signs of other disease (for example, weight loss with CKD).
Additionally, opportunities can be missed when cats are in the clinic for other reasons, such as the treated hyperthyroid cat attending for thyroxine measurement. Therefore, raising owner awareness of hypertension has value to increase understanding of why it is important to present cats for screening – particularly if they have associated conditions (for example, CKD and hyperthyroidism).
While ideally senior clinics are created, including measurement of bodyweight/condition, urinalysis and SBP measurement, this can take time and effort, so starting with a process of measuring SBP in cats with azotaemia, for example, and building from this, can make increasing SBP measurement feel more achievable in a busy clinic.
Veterinary nurses are vital in improving frequency of SBP measurement in clinics via specific nursing clinics, measurement of SBP during consulting periods and in hospitalised patients, as well as improving owner communication and awareness.
Pricing of SBP measurement can be a contentious issue and create its own barrier to diagnosis of hypertension, although research shows this may not be as much of a barrier to owners as we perceive or assume. In some clinics, SBP may be priced in different ways by different staff members and even have more than one code and cost.
A clinic meeting to see how this can be affordably incorporated into consultation fees, or blood/urine pricing bundles, may be productive.
Importantly, value exists in recording normal readings in healthy older cats, to allow observation of increasing SBP trends in individual cats. Figure 3 shows different areas of focus in improving the detection of hypertension.
In 2024, CVS ran a group-wide clinical project to increase early identification and treatment of hypertension, which was named QI winner in the RCVS 2024 Quality Improvement Awards.
The initiative nominated people in each clinic to promote measurement of blood pressure and become a point of contact for communicating with owners and staff.
Additional CPD and resources were provided. The initiative involved an audit of blood pressure measurement in clinics prior to the project, revealing only 1% of animals aged seven years and older had annual SBP screening. CPD sessions were held to identify barriers to SBP measurement, including confusion around pricing, confusion and confidence around equipment use, and lack of time and equipment. These barriers were tackled with the purchase of equipment, but also ensuring availability of equipment (for example, an all-in-one dedicated container), providing clarity around charging, and specific marketing and identification of at-risk cats, such as those with CKD and hyperthyroidism.
During the 2022-23 re-audit, a 110% increase in SBP screening was recorded at the focus sites with a 34% increase in prescription of anti-hypertensive medication, showing that increasing the frequency of SBP measurement results in identification and treatment of hypertensive cats.
Read more about this initiative online (bit.ly/42Uqng9) and consider how you could apply some of the ideas to your clinic.
A growing body of research is helping us understand more about hypertension in our feline patients, which is fantastic, but in parallel implementation of initiatives to normalise routine SBP assessment of senior cats must be the aim.
What are the barriers in your clinic? This may vary between hospitals, so a bespoke and manageable plan, starting with increasing SBP measurement in the most at-risk patients, could be the subject of your next clinic meeting.
